ORA 6571 Function doesn't guarantee NOT to update database

I have a function in a package, say APKG.AFUNC(), that takes a parameter, does some processing, and returns a VARCHAR2. This function works fine in a PL/SQL cursor. However, when I call this function like this (a trivial example) at the SQL*Plus prompt:

SELECT Apkg.AFunc('abcd') FROM dual;

Oracle returns the ORA-06571 error. The errors text (from the "oerr" command) says:

06571, 00000, "Function %s does not guarantee not to update database"
// *Cause: A plsql function that does not have a pragma
asserting that it
// does not write any database state is referenced in a sql statement.
// Such functions cannot be used in sql statements.
// *Action: Recreate the function and/or the functions it calls
with the pragma

The function does NOT update the database, but other procedures within the package do - but they are NOT called from this function. If I
remove this function from the package and make it stand-alone, and remove calls to ALL other procedures/functions (including raise_application_error), the above SELECT statement works.

However, I would like to keep this function in its package, along with the raise_application_error call to handle errors. What is the pragma referenced in the above error message text? A scour through the manuals only mentions the exception_init pragma. I could not find any type of reference to Oracle pragmas in general, or (more usefully) the pragma I need to solve my problem.

Can someone help me?

Thanks,

James B. Corbin (Jim.Corbin_at_DaytonOH.NCR.COM) NCR Corporation - WWIS, US Apps, US Financial & Planning Systems 1529 Brown Street, Building EMD-6 Dayton, OH, 45479 USA Tel: (513) 445-6309 (VP 622-6309) Received on Wed Oct 23 1996 - 00:00:00 CEST